I need help with science:

A uniform wooden plank with a mass of 75kg and length of 5m is placed on top of a brick wall so that 1.5m of plank extends beyon

jek_recluse [69]

Answer:

x₂ = 1.33 m

Explanation:

For this exercise we must use the rotational equilibrium condition, where the counterclockwise rotations are positive and the zero of the reference system is placed at the turning point on the wall

Στ = 0

W₁ x₁ - W₂ x₂ = 0

where W₁ is the weight of the woman, W₂ the weight of the table.

Let's find the distances.

Since the table is homogeneous, its center of mass coincides with its geometric center, measured at zero.

x₁ = 2.5 -1.5 = 1 m

The distance of the person is x₂ measured from the turning point, at the point where the board begins to turn the girl must be on the left side so her torque must be negative

x₂ = $\frac{M_1g }{m_2 g} \ x_1$

let's calculate

x₂ = $\frac{100}{75} \ 1$

x₂ = 1.33 m

7 0

3 years ago

As a battery is used to charge a capacitor, does the overall charge inside the battery get smaller, greater, or stay the same?

irga5000 [103]

The Charge Gets Smaller.

5 0

3 years ago

Which of the following statements describes a battery?

LiRa [457]

Answer:

The negative electrode of a battery has an excess of positive charge

Explanation:

This is because in every battery, there is a negative electrode ( cathode ) and only positive charge is deposited on it.

For other statements:

Batteries donot store electric charge but they store chemical energy

Some batteries donot use metals for the flow of electrons, but some use hydrogen gas at a pressure of 1 atmosphere.

8 0

3 years ago

The nuclear equation is incomplete.<br><br><br>What particle completes the equation?

Romashka-Z-Leto [24]

Answer:

$_{6}^{12} C$

Explanation:

$_{1}^{1}H+_{7}^{15}N ---> _{6}^{12} C+ _{2}^{4}He$

1+7 = 6+2 =8 -protons

1+15 = 12+4 = 16 - protons +neutrons

3 0

3 years ago

Ballistic data obtained on a firing range show that aerodynamic drag reduces the speed of a .44 magnum revolver bullet from 250

m_a_m_a [10]

Answer:

0.363999909622

Explanation:

F = Force

m = Mass = 15.6 g

C = Drag coefficient

ρ = Density of air = 1.21 kg/m³

A = Surface area = $\dfrac{\pi}{4}d^2$

v = Terminal velocity = $v=210\ m/s$

s = Displacement = 150 m

$a=\dfrac{v^2-u^2}{2s}$

Force is given by

F = ma

$F=\dfrac{1}{2}\rho CAv^2\\\Rightarrow ma=\dfrac{1}{2}\rho CAv^2\\\Rightarrow m\dfrac{v^2-u^2}{2s}=\dfrac{1}{2}\rho CAv^2\\\Rightarrow C=2\times m\dfrac{v^2-u^2}{2s}\times\dfrac{1}{\rho Av^2}\\\Rightarrow C=2\times15.6\times 10^{-3}\dfrac{210^2-250^2}{2\times 150}\times\dfrac{1}{1.21\times\dfrac{\pi}{4}\times (11.2\times 10^{-3})^2(210)^2}\\\Rightarrow C=-0.363999909622$

The drag coefficient is 0.363999909622 (ignoring negative sign)

4 0

3 years ago